第二页访问时禁止错误403

Question

I have a blog with html form / php script for uploading new blog posts and I kept hitting a 403 Error, which I thought I had fixed, but obviously not.

This morning I visited my blog add-post.php page, which in turn sends the data to add-post-php.php for processing. When I press submit the blog post details are entered into the database table and I'm redirected to the post page, which shows up correctly.

So then I go to add a second post using exactly the same process, only this time when I press submit and get redirected to the add-post-php.php I get the old "Forbidden 403" file pop up on my screen.

What's the deal? Any ideas why this could be happening?

My .htaccess is:

Options -MultiViews

DirectoryIndex posts.php

RewriteEngine On

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d    

RewriteRule ^posts/([0-9]+)/?$              posts.php?currentpage=$1 [NC,L,QSA]

RewriteRule ^section/([\w-]+)/?$            section.php?section=$1 [NC,L,QSA]
RewriteRule ^section/([\w-]+)/([0-9]+)/?$   section.php?section=$1&currentpage=$2 [NC,L,QSA]

RewriteRule ^posts/([\w-]+)/?$              posts.php?category=$1 [NC,L,QSA]
RewriteRule ^posts/([\w-]+)/([0-9]+)/?$     posts.php?category=$1&currentpage=$2 [NC,L,QSA]

RewriteRule ^post/([0-9]+)/([\w-]+)/?$      post.php?id=$1&title=$2 [NC,L,QSA]

RewriteRule ^sites/([0-9]+)/?$              sites.php?currentpage=$1 [NC,L,QSA]

RewriteRule ^posts posts.php
RewriteRule ^section section.php
RewriteRule ^sites sites.php

RewriteRule ^about about.php
RewriteRule ^advertise advertise.php
RewriteRule ^subscribe subscribe.php